Investigation of Metrological and Agricultural Drought in South-Eastern Sindh

Abstract

The geographical location and extent of Pakistan makes it one of the most vulnerable countries to be affected by climate change. The country basically lies in the tropical zone where evapotranspiration losses are associated with extreme high temperatures. The arid and semi-arid regions of Pakistan receive less than 250 mm of annual rainfall making it a subject to frequent and intense droughts. This study is conducted for three districts of Sindh namely Sanghar, Tharparkar, and Umer Kot. The observational as well as gridded data sets of Tropical Rainfall Measuring Mission (TRMM) and Climatic Research Unit (CRU) for precipitation and temperature respectively were used to determine the meteorological and agricultural drought at both tehsil and district level from 2000 to 2018. Drought indices namely Standardized precipitation Index (SPI), Reconnaissance Drought Index (RDI), Deciles Index (DI), Agricultural Standardized precipitation Index (aSPI) and effective Reconnaissance Drought Index eRDI have been used for identification and spatially plotting of drought years. The drought years identified by these drought indices were 2000, 2002, and 2017. In order to identify the impact of meteorological drought over agriculture, the Normalized Difference Vegetation Index (NDVI) and Vegetation Health Index (VHI) were analyzed spatially in each of the drought years. Furthermore, NDVI and VHI anomalies were plotted spatially to determine the effect of rainfall variability on vegetation. A drought monitoring equation is generated for the study area which will help the drought managers and disasters agencies to develop contingency plan of climate smart agriculture towards sustainable development over the region.